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Abstract 


The early decades of sound recording are a period of rapid change in both recording 
technology and performance practice. Primitive recording equipment, minimal 
documentation and musical pitch varying by time and location make it difficult for 
archivists to know the proper playback stylus size and playback speed. Using four 
very large data sets of both pristine and worn media, combined with a highly 
consistent selection methodology, this study investigates the level of accuracy 
attainable when selecting stylus size and determining playback speed. The analysis 
shows it is possible to determine, with high certainty, the correct playback stylus 
size per record label during this period of early sound recording. The analysis then 
shows that the distribution of pitch follows a Gaussian distribution of randomness; 
meaning, it is not possible to know with certainty the proper playback speed. 
Commentary discusses the cultural environment of the early recording era and the 
implications for archival practice today. 


Historical Context 

Every field of critical inquiry that engages with the past inevitably must address 
questions that are very difficult, if not impossible to answer. What color were 
dinosaurs? What was before the Big Bang? On what day was Henry V born? Was 
Thomas Jefferson a good violinist or a bad violinist? Aristotle wrote, "Everyone 
desires to know”. Our desire for knowledge and certainty propels human inquiry, 
especially when that inquiry involves the roots of our identity. The insatiable need 
to know leads us to uncover the previously unknown, even though the answer, if 
ultimately found, may prove dissatisfying, either because it challenges our 
assumptions, or is simply not very interesting after all. Furthermore, we must 
embrace and apply new information and knowledge appropriately; and accept when 
we do not and may not ever know certain information, and accept that our actions 
are based on assumptions and opinion, rather than facts, however well founded. 

On the front of the Stephansdom Cathedral in Vienna are 2 iron bars, each about a 
meter long, one about a hands’ width longer than the other. Installed in the Middle 
Ages, these were the official Viennese measurements of a yard for use by local and 
traveling merchants for general commerce in the city. There was a measure for 
linen, and a separate measure for drapery. A traveling merchant adjusted his 
practice to the local standards. For hundreds of years, this was the state of 
standardization in the world. 

The early part of the 20 th century was a time of great changes. The Industrial 
Revolution brought prosperity to a new middle class. New modes of transportation 
brought far-flung parts of the world into contact. As manufacturing expanded with 
the introduction of interchangeable parts, the need for standards in weights and 
measures became apparent. Likewise, manufacturers soon found ways to create 



entertainment goods for the new mass market. 

At the same time, many technologies were new and poorly understood. Electricity 
was lighting homes before anyone understood grounding. Electric motors and 
microphones 1 were crude. Their use in sound recordings was limited prior to the 
development of electrical recordings ca. 1923. Speed was hard to measure and 
regulate 2 . There was no understanding of, much less the means to measure, 
distortion. There were no definitions for frequency response and level, speed 
fluctuation, gain, or linearity. 

Standards as we understand and use them today, were taking root in the early 
decades of the 20 th century. As the formerly isolated peoples of the world began to 
interact more frequently, they shared their goods and cultures. To work together 
they needed to adapt or adopt the things they wished to share. For musicians to play 
together they needed a common pitch and tuning system. Between 1895 and 1910 
there were three international meetings to define the frequency of the A above 
Middle C. At those meetings the standard rose from 430 to 435, then to 440Hz 3 . It 
takes a long time for a standard like this to become widely practiced. Musicians, like 
people in all walks of life, can be slow to adopt change. More practically, instruments 
are not replaced very frequently. Church organs and string instruments may last 
centuries 4 . The physical dimensions of an instrument affect its characteristic pitch. 

Into this brave new world of evolving standards, fluid pitch, and new inventions 
arrives recorded sound. One might reasonable say the early technicians and 
recording engineers were "making it up as they went along”. For some 
experimenters we have lab notes that document the goals, methods, and discoveries 
of their work 5 . For some recording sessions, the recording staff kept notes. Thomas 


1 The microphone was developed independently by Emile Berliner and David Edward 
Hughes in the 1870s. It is one of the fundamental precursors of Alexander Graham Bells’ 

2 It’s one thing to make an electric motor go 'round. It another thing to make it go 'round at 
a consistent speed, an imperative for sound recordings. 

3 The issue of pitch would remain important. When the new International Standards 
Organization (ISO) was formed in 1955, one of their first tasks was to adopt a uniform 
frequency of A=440 as ISO 16. This is where we get the expression "Standard Pitch”, by 
which we mean A=440. 

4 Woodwind and brass instruments rarely last more than a generation. Professional 
musicians may "blow out” an instrument in 5-10 years. This idea was put to me by Jay 
Krush, founding member of Chestnut Brass Company, an ensemble that specializes in 
playing early brass instruments. Most of the historic instruments they've been able to 
collect are real dogs. "The good ones were played until they died. The ones that survive 
were owned by amateurs who rarely played them, then threw them in a closet until their 
grandchildren found them." 

5 An excellent summary of work by the Edison staff: STYLUS SHAPES and SIZES: Preliminary 
Comments on Historical Edison Cylinder Styli, by Bill Klinger, Chair of the ARSC Cylinder 
Committee. 


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Edison left behind some very detailed technical drawings. Unfortunately, just as 
they were "making it up as they went along”, they didn’t really know what 
information might be worthwhile to keep - either for the benefit of their developing 
profession, or for future researchers. 

Despite the many limitations of weight driven lathes and large acoustic horns, and 
the uncertainties about practices in the early decades, we nonetheless have 
documents of the cultural record that do not exist from earlier times. Audiovisual 
records are what distinguish the cultural record of the 20 th century. This is what 
drives our curiosity to understand these media. We gain both a better 
understanding of our history during this important period of change, and as 
audiovisual archivists, an appreciation for the roots of our profession. 

The Problem 

There are serious challenges to determining the correct way to reproduce these 
recordings. At what speed was the lathe turning on the day this particular recording 
was made? What pitch did the musicians tune to? How accurately regulated was the 
speed of the lathe? Did the musicians re-tune between takes? Were the musicians 
from different traditions and choose a compromise pitch for the recording date? 6 

As we can see, there are many contextual problems to determining "what is the 
correct speed” of an acoustic 78rpm disc. Lacking strong documentation from a 
period of general uncertainty, we are forced to work with the recording engineer’s 
final product, that is the discs themselves. The overwhelming majority of the discs in 
existence are heavily worn from many years of use and enjoyment. This wear means 
our work in reproduction, especially stylus selection, must take this deterioration 
into account in the data we gather. Just as archaeologists must interpret fossils and 
astronomers must compensate for the affect of the Earth’s atmosphere when 
peering into the heavens, record wear obscures our data 7 . 


6 The author is grateful to Clara Blood, DMA, for furnishing this fascinating discussion on 
this topic as viewed from a different vantage: Oboists as keeper of orchestral pitch. 
http://www.oboeclassics.com/Burgess.htm 

7 This assumption regarding the impact of record wear is brought into question later in this 
paper. 


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The Digitization Process 

The playback and digitization process followed the widely adopted best practices of 
the trade: 

• Hand-delivered from home institutions 

• Cleaned with Keith Monks Record Cleaning Machine (distilled water) 

• Pictures of the label and matrix (Nikon D810 at 400ppi TIFF) 

• Technics SP-15 Turntable fitted with needles by Expert Stylus 

• 4 KAB preamps 

• 8 Channel PrismSound ADA-8XR (96kHz/24bit) 

• Pitch detection 

• Trim and render derivatives for National Jukebox 8 

• Harvest and store AES-57 metadata 



Figure 1 


Figure 1. This is the playback system built for this work. By mounting 4 tone arms, 4 different styli can 
be reproducing at the same time. The engineer can compare, in real time, the sound of each stylus and 
rapidly switch between them. Compared to the traditional method of manually changing the stylus, then 


8 All the work for the Library of Congress is destined for this site: 
http : / /www.loc.go v/j ukebox / 


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replacing with another, then changing back, etc., there is no need to remember what one stylus sounded 
like. With the push a button the operator can compare, not 2 but 4, different styli rapidly. 

The Data 

The core sources 9 for this study have several attributes that make the data 
especially relevant: 

• The sample sets are large: more than 9,000 disc sides. 

• The data include international sources. 

• A period of approximately 20 years of early recording practice is covered. 

• All work was performed to the same specifications. 

• All work was performed with the same equipment. 

• All work was performed by the same engineer. 

These are the four data sets used in this study: 

• Victor Talking Machine Company 

The Victor discs are the stuff collectors, engineers and historians dream of. They are 
in pristine condition, beautifully preserved at the Eldridge Johnson Museum. Most of 
the rare and international titles in this study are in this collection. 

• Edison Diamond Discs 

These are factory originals, also in pristine condition [‘reference discs' they might be 
called], under the care of Gerald Fabris at the Edison National Historic Park. This 
data set includes multiple takes of the same selection. 

• OKeh Records 

Unlike the Victor and Edison discs, the OKeh disc collection was assembled from 
discs that had circulated in the wild. They had been bought in stores, played, 
enjoyed, and handled under a random set of circumstances. They are far more 
representative of the samples available to most studies. They are holdings of the 
Library of Congress, at the Packard Campus of the National Audio-Visual 
Conservation Center, in Culpeper, VA. 

• Mick Moloney Collection of Irish-American Music and Popular Culture 


9 The data for this paper was collected from two contracts performed for the Library of 
Congress and another contract for New York University. It is important to note that none of 
these contracts required the acquisition of data for this study. Flaws in the methods of data 
gathering and analysis are evident throughout. However, the findings are extremely clear, 
more than overcoming these flaws. Efforts are taken throughout the paper to point out 
where a more disciplined approach could have been followed, and how better method may 
or may not have produced different results. The raw data are available at 
www.georgeblood.com. 


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This New York University Collection is included to represent the general population, 
as a control and for comparison 10 . Insofar as the focus of the collection is Irish 
music, there is no preference for a given label. Like the OKeh Records samples, these 
are discs that had circulated in the wild. 

The highly uniform digitization process allows us to investigate variation within 
each collection and between the four sets, and to explore the sources of those 
variations. 

The findings from each data set are first presented separately. 

PART 1, STYLUS SIZE 

Victor Talking Machine Company 

The Victor recordings data represents 3,500 sides. When the Victor Talking Machine 
Company operated in Camden, NJ, they sent copies of each title to the Free Library 
of Philadelphia. Like all libraries, only about 2% of their holdings circulate, and the 
sound recordings followed this pattern. When the Library chose to de-accession 
their analog sound recordings, the Victor discs moved to the Eldridge Johnson 
Museum, run by the Delaware Department of Parks and Recreation. This is an 
enormous collection of rarely played discs. 

Most of the recordings at the Eldridge Johnson Museum are widely distributed. The 
selection of discs to digitize was led by Samuel Brylawski, Editor/Project Manager of 
the Encyclopedic Discography of Victor Recordings /American Discography Project 
at the University of California at Santa Barbara, someone who we can reasonably 
assume to know a thing or two about the Victor catalog. This project selected very 
rare recordings of Eastern Europeana, South American, and ethnic recordings. 
Therefore, we have an international distribution over a range of two decades, 
making our sample set both large, and widely representative. 


10 It is important to point out the data from the Moloney Collection used in this study 
includes both acoustic and electrical recordings. Therefore, it is far from perfect for 
comparison with the Victor, Edison and OKeh data. 


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Figure 2 illustrates that within our sample set, some time periods are better 
represented than others. 

This sample bias is the result of selections focused on rare ethnic titles. While this 
gives the sample a highly desirable international distribution, the results are less 
evenly representative of the time period. A more carefully designed study might 
have added samples where the distribution has a low number of titles. However, the 
data will show this would not have had a significant impact on the results. 

During this period there is great variation of performance practice by region. This is 
very important for the investigation of speed and pitch, which will be discussed in 
the second half of this paper. The sample set has the advantage that the recordings 
were made by teams from the same label. 


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Stylus Size Distribution 

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1.5 1.8 2.0 2.3 2.5 2.8 3.3 3.8 4.0 


Figure 3 11 


Data from the Victor discs show this remarkably clear finding. One stylus size, 
2.8mil, was chosen for more than half the Victor sides digitized. The data were next 
examined for an explanation of the secondary strengths at 2.0, 2.3 and 2.5mil. 

The data were analyzed to determine whether the distribution of sizes matched the 
distribution over time. Higher numbers of sides are expected in the subsets at 1916- 
1917 and later because there are more data points to begin with (cf. Figure 2). 


11 Please pay attention to the scaling on the left side of these charts. Some times it is scaled 
for maximum resolution, and other times scaled to a fixed unit to facilitate comparison 
between charts. 


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2.3 



Figure 4b 


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2.8 


300 


250 


200 


150 


100 


50 







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Figure 4d 


And indeed that is what we see in the data. The peaks in the stylus size subsets 
mirror the peaks in the aggregate data. Further, no trend appears in the data. The 
data do not show size A being used in the early 19-teens, then a few years later, 
toward the 1920’s, a different size is dominant, and so on. The distribution of 2.0, 
2.3 and 2.5 is fairly even, with significantly more 2.8 across all time periods. 


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The data were next analyzed by the recording location. Just as with the distribution 
of the stylus size by catalog number, we find the same pattern: all locations 
dominated by 2.8 mil, followed by smaller sizes, as shown in Figure 5a-5d. 


Camden 



Figure 5a 


New York 



Figure 5b 


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Havana 


70 

60 

50 

40 


30 

20 

10 

0 


1.5 



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3.8 4.0 


Figure 5c 



In conclusion, when working with acoustic Victor discs, a 95% certainty for proper 
stylus size is obtained by reviewing just four stylus sizes. If this sample were 
random, that is if it followed the normal distribution under a bell curve, the data 
would be symmetrical, with an equal distribution of samples to left and right of the 
peak. However, there are nearly lOOx more samples of smaller stylus sizes to the 
left of 2.8 than larger stylus sizes to the right of 2.8, indicating something is causing 
the non-random distribution. 


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Might the intended cutting stylus size have been 2.8mil? As the cutter was used, was 
it worn down, to a smaller and smaller size, until it was replaced? 


Edison Diamond Discs 


The Edison recordings are represented by 2,500 sides. Edison’s company retained 
samples of most discs it recorded. The collection includes released discs, multiple 
takes from which the released version or versions were selected, as well as 
unreleased material. Similar in scope and condition to the Victor discs, this is an 
enormous collection of rarely played discs. 


Edison Stylus Size 

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1600 - 

1400 - 

1200 - 

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).7 1.5 1.7 1.9 

2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 

Stylus Size 


Figure 6 


The results of analyzing stylus selection for Edison Diamond Discs (Figure 6) are 
likewise very clear. They are also very puzzling. Edison, as an engineer, was 
meticulous in the specifications for his inventions, their manufacture and use 12 . 
Engineers, collectors and historians have long struggled with a great disparity: we 
generally agree that Diamond Discs "sounding better”,(whatever that means) when 
played with a very small stylus; and yet, the documentation left by Edison indicates 
a larger, 3.5 or 3.3 mil, stylus size should be used for playback. 


12 Cf. footnote 3. 


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Disc grooves are three-dimensional: top to bottom, left to right, and along their 
length. In practice, either the lateral (in hill and dale) or vertical (in lateral cut) 
component is absent 13 . Discussions of stylus shape focus on the cross-sectional view 
of the "stylus in the groove”; that is, how the stylus fits and tracks side-to-side or up- 
and-down. Less frequent are discussions that consider the relationship between the 
longitudinal shape and size of the cutter and that of the playback stylus. The cutter, 
by definition, will have a sharp point: it may be 3.5 mil across but it is shaped 
(ground or cut) into a sharp point to cut into the recording medium (at first wax, 
then later lacquer). A playback stylus that had a sharp edge, and short longitudinal 
profile, would naturally tend to cut the disc while being played. Shellac is much 
harder than wax, but the problem remains. Further, remember how these media 
were played: a stylus wiggled in the groove, then transferred that wiggle to a 
diaphragm that transduced the motion into varying air pressure (a.k.a. sound) 
which was amplified by a horn - the larger the horn, the greater the amplification. 
The stylus both reproduced the sound in the groove, and moved the horn apparatus 
across the disc 14 . To keep the stylus in the groove firmly enough to move the horn, a 
great deal of pressure was needed. The nominal weight of the diaphragm and the 
suspended horn is 4-5 ounces. LP turntables track at below three grams! As the 
surface area of the playback stylus is reduced the weight of 4-5 ounces is spread 
over a smaller and smaller area. This means more weight is applied to the groove, 
leading to increased wear. The sharp cutting stylus incises fine detail along the 
groove. The fatter playback stylus, needed to carry the weight of the diaphragm and 
horn, cannot capture the information left behind by the cutting stylus. It spans 
multiple hills and is unable to reach into the dales 15 . 


13 Most discs are cut by modulating the groove side-to-side ("lateral cut”). Edison media are 
cut up and down ("vertical cut”), a.k.a. "hill and dale". Vertical cut discs have more 
consistent groove geometry. However loud sounds tend to eject the stylus from the groove. 
Ultimately lateral cut was used by most manufacturers, and became the standard for LPs. 

14 Edison Diamond Disc players include a feed screw to move the stylus and horn across the 
disc. This requires the pitch (number of turns per unit distance) of the disc and feed screw 
to match. Otherwise the feed screw would cause the disc to skip forward or backward. 

15 For a discussion on tracing distortion see Di Toro, J. SMPTE 29, 493, 1937 


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Figure 7 


Higher frequencies have smaller wavelengths. Smaller wavelengths are smaller groove 
sizes (lower waves in the image). Large styli distribute the weight, but don’t fit into the 
groove (right). The center stylus fits Edison’s specification. The left stylus sounds 
better. 

Might it be that Edison’s working assumptions regarding the relationship between 
the cutting stylus size and shape 16 and the playback stylus size and shape were 
incorrect 17 ? Instead might it be that Edison’s cutting stylus, especially in the hill and 
dale topology, resulted in a groove profile best reproduced by a very different 
stylus: a size and shape not easily obtained at that time? 


16 Edison’s grooved media used a geometry often called "door knob” shape, from the 
popular shape of Victorian era hardware. Other manufacturers used conical shape, 
triangular in profile, or a triangular shape with the point removed. 

17 The assumption is the playback stylus should have the same profile as the cutting stylus. 
This is impossible to achieve. The shape might be very, very close, but due to irregularities 
in the recording medium, and the replication process, as well as wear of both the cutting 
and playback stylus, an exact match cannot be achieved. 


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OKeh Records 


The work on Victor and Edison discs was performed under a contract specifically 
intended to generate content for the Library of Congress’ National Jukebox 18 . A later 
contract was awarded for digitization of general audiovisual holdings of the Library. 
The Moving Image Broadcast and Recorded Sound Division (MBRS) selected a large 
span of OKeh 19 Records for preservation digitization under this contract. 

The samples are acoustic recordings, the earliest of which are sometimes vertically 
cut (like Edisons), spanning approximately a decade. Unlike the Victor and Edison 
discs in this study, these discs are heavily worn from general circulation and years 
of enjoyment by their owners. Their condition varies widely - very good to poor, 
and, rarely, very fine like the Victor and Edison discs. For our study these discs are a 
contrasting label and contrasting condition. They are from the same time period, 
and have been digitized using the exact methodology as the Victors and the Edisons 
(e.g. using four tone arms, etc). 


OKeh Stylus Size 

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1UUU 

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4UU 

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1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 

0.7 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 


Figure 8 


Whereas the Victors showed a clear preference for 2.8mil and Edisons for 0.7mil, 
OKeh acoustic discs have an equal preference for 2.3mil. In contrast to where the 


18 www.loc.gov/jukebox 

19 Fun fact: At the beginning of the 20 th century "OK” was a popular, new expression. While 
the spelling evolved to "okay" or simply "OK”, at this time it was spelled "okeh”. The label’s 
name is a play on this new expression and the founder’s initials Otto K.E. Heinemann. 


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Victors show the prominent 2.8 followed by the secondary peaks to the left of 
smaller sizes, the OKeh data show an even distribution to the left and right of the 
peak, of larger and smaller stylus sizes. 

Might the engineers at OKeh have changed cutting styli more frequently than was 
the practice at Victor? Despite the clearly audible signs of wear and aging, the OKeh 
data on stylus size are among the clearest of all the data sets in this study. Might the 
long-held assumption in our trade, that stylus selection includes compensating for 
groove wear, be wrong? Could it be that usage wear does not fundamentally warrant 
a stylus choice different than would be made on a pristine disc? 

Mick Moloney Collection of Irish-American Music and Popular Culture, New 
York University 

The NYU/Moloney Collection focuses on genre rather than label. The playback stylus 
size selection for the discs shown in Figure 9 is included to represent the 
distribution of stylus sizes in the general population of discs available throughout 
the 78rpm era. 


Misc. Labels 



Figure 9 


This data affirms that the single engineer who digitized all four sets (Victor, Edison, 
OKeh and Moloney discs) was thorough and considered multiple stylus sizes during 
his selection process. The chart also shows a distribution clearly different from 
those from the label-specific data, where there is a clear preference for one size over 
all others. Here we see, in a random selection of labels, no clear choice of stylus size 
is evident. 


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All Discs 

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1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 

1.7 1.5 1.7 1.9 2.1 2.3 2.5 2.7 2.9 3.1 3.3 3.5 3.7 3.9 


Figure 10 


The chart in Figure 10 combines all the data from Victor, Edison and OKeh. Both 
show many strong peaks and no clear preference, supporting the assertion the 
NYU/Moloney collection is representative of the general population, and the label 
specific data is clearly different from the general population. The peaks do not 
match because the underlying labels are different. The goal is not to say the two 
charts match. It is to show that when multiple labels are present in the data there 
are multiple peaks. When a single label is examined in large quantities, a clear 
preference emerges. 

One final data set for stylus selection... 

Marcos Sueiro Bal Double Blind Study on Stylus Selection 

At the 2015 International Association of Sound and Audiovisual Archives (IASA) 
Conference in Paris Marcos Sueiro Bal, Senior Archivist at WNYC in New York and 
co-chair of the Association for Recorded Sound Collections (ARSC) Technical 
Committee, presented preliminary results of his study on stylus selection. Sueiro Bal 
made short digital files of disc transfers. Each disc (presented below in its own 
chart. Figures 11a- lie] is a different genre. Each disc was played multiple times, 
each time with a different stylus size and shape (A-E or A-F in the following 
examples). There were 5 or 6 stylus sizes for each of 5 different musical genres in 
preparation for a double blind test, he asked a colleague to rename the samples to 
obscure information about the styli used for playback of the samples. Sueiro Bal 
asked respected audio transfer engineers to review the files at their leisure using 
their preferred playback environment, and to report their preferences. Two 


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respondents 20 took the test twice. The responses provided 49 data points for each 
musical selection. 

The assumption has been that an experienced engineer with training on what to 
listen for is needed to choose the proper stylus size; yet, only one test shows a 
consensus preference. 

The results of the tests are presented in the Figures lla-llf. 


Double Blind Stylus Selection Test 1 


C 

a 

o 

u 

c 

o 


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Stylus 


Figure 11a 


20 Marcos Sueiro Bal himself and George Blood, the author of this paper. 


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Double Blind Stylus Selection Test 2 

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c 15 

3 

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u 

C y\ r\ 


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<u 

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5 


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A B C D E F 

Stylus 


Figure lib 


Double Blind Stylus Selection Test 3 



Stylus 


Figure 11c 


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Double Blind Stylus Selection Test 4 



Stylus 


Figure lid 


Double Blind Stylus Selection Test 5 

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£ 15 

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Figure lie 


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Double Blind Stylus Selection Data Stacked 



Figure Ilf 


The last chart. Figure Ilf, includes all the data points for all five tests together. 

There is no distinct preference for any given ordinal choice; that is, there is not a 
bias toward choosing the first item heard, for instance. From this distribution it 
appears the engineers taking the test took their time to carefully consider all the 
alternatives. 

The wide range of results for each sample calls into doubt whether we can assert 
that the choices of stylus size, even by professionals, results in the "best”, "proper" 
or "correct” stylus. This doubt is reinforced by both respondents who took the test 
twice and gave different preferences in most instances. 

Summary Conclusions on Stylus Size Selection 

• The proper stylus for a given label in a given era can be known with high certainty. 

- Victor: 2.8mil is the best stylus size. In practice 2.0, 2.3 and 2.5mil sizes are 
needed 

due to apparent wear in the cutting stylus on some recordings. 

- Edison: 0.7mil is the best stylus size. 

- OKeh: 2.0 is the best stylus size. 

- NYU/Moloney: aggregate data demonstrates a wide range of practice during 
the period before 1923. 

• Wear may not affect stylus choice after all. 


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• Stylus selection by experienced and respected engineers is highly variable and not 
repeatable according to the generally accepted standards of the scientific method. 


PART 2, SPEED DETERMINATION 

While pitch and speed are inextricably linked, they will vary independently of each 
other during recording. Just as two disc cutters might operate at a different speed, 
two artists performing to the same lathe might tune to a different pitch. During 
playback however, without additional information, it is not possible to separate the 
two effects. The result might be due to the cutting speed, or the tuning pitch, or a 
combination of both. Pitch A might be 435Hz or 440Hz. Rotational speed might be 
71.29rpm or 78.26rpm. However, if A=440Hz=78.26rpm, then A=435Hz t 
71.29rpm. 

As discussed in the introduction, speed determination of recordings from the early 
20 th century is challenging due to widely varying practices for reference pitch, 
difficulty controlling mechanical speed of the recording lathe and playback 
turntable, lack of documentation, and other technical and cultural factors 21 . 

• Parameters are moving targets. 

- A=? 

- How fast does a turntable spin? 

- How do you control that speed? 

- Regional differences in pitch and/or recording practice 

- Ambient temperature changes pitch of the instrument between takes 

- A work is otherwise too long to fit on one side 

- Simply playing out of tune (or different temperament) 

- Ego/Ability (want to appear to sing higher or play more "brilliantly”) 

- Who cares? 

- Operator error (during recording or playback) 

As demonstrated for stylus size in the example of the NYU Moloney Collection, our 
control group, it is possible the apparent randomness could be the result of many 
different variables laid on top of each other. That is, if the data is parsed into its 
component subsets, discrete causes might emerge. 


21 Other factors may introduce variation or noise into the data. These include digitization 
engineer choicing up or down to the nearest semitone, discs whose speed varies across the 
duration of the disc, wow and flutter, non-equal tempered tunings, etc. Each of these may 
impose additional considerations upon a given side. However, their frequency of 
occurrence is low, and therefore only noise in the data, not influencing the conclusions. Cf. 
the discussion and charts that follow. 


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Or they may not. Recall that the distribution of stylus sizes for the Victor discs did 
not vary over time or by location. 

In the traditional method for pitch detection the engineer matches an external pitch, 
whether it be from a tuning fork, pitch pipe or other source, such as a small 
keyboard 22 . 

Pitch detection for the work in this study used a polychromatic tuner 23 . This 
measures all 12 pitches, in real time, at the same time. Pitch is set very rapidly, very 
precisely and with high repeatability. This is a significant advance over traditional 
methods. 

For this project, the clients, the Library of Congress and New York University, 
specified that the speed of the discs be varied such that A=440. Noting that 
discussion of the merits of that choice are beyond the scope of this paper, the author 
wishes only to point out that the choice is highly defensible and, for this study, the 
key to producing meaningful data on speed and pitch selection during the acoustic 
era. Because, if playback is to be subject to "what I like best”, then the data will vary 
just as it did in Marcos Sueiro Bal’s study on stylus selection. There would be no 
anchor around which to compare the results. 

With the target fixed, investigation of variance from that target is possible. The same 
would be true if the target were A=435Hz or rpm=78.26 or 77.92. The locus of the 
data changes, but the variation and distribution around the reference does not. 

The charts are plotted with percentage deviation from A=440Hz on the vertical axis 
(+/- 9.9%), and the number of samples at each 0.1% increment along the horizontal 
axis. 


22 A few practitioners have perfect pitch. Some choose to leave the discs at 78.2 6rpm and 
avoid this topic entirely. Others choose what they like best based on their musical 
judgment, and may take into consideration a pitch detection method. 

23 PitchLab is available for iPhone iOS and Android smart phones. Rare 12-pitch 
Stroboconn and Petersen tuners, no longer manufactured, are also suitable for this work. 


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Victor Talking Machine Company 


Speed Variation Distribution 



Figure 12 


This result on speed variation in the Victor discs is the exact opposite of the 
distribution found in the stylus sizes. Where the stylus data show cleared peaks, 
these data are random. They follow normal distribution - also known as a bell curve 
- as predicted by the central limit theorem. 


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Since many of the recordings in this data set were made in remote locations under 
difficult circumstances, we can assume more chances for variation in the Victor 
recordings. However, as shown below, this distribution is found in all four data sets. 

The historical record includes information on pitch over time and by location. The 
literature is full of information purporting to establish rotational speed as well. If 
either of these were true, we anticipate peaks in the data. Anticipated peaks include 
historical pitches, such as frequencies A=415, 430, 435, as well as 440, and proposed 
target rpm speeds such as 71.29 and 77.92. 

However, when the graph is annotated with these values where we anticipate peaks, 
we instead find areas of low sample count. Where there are peaks in the data they 
do not correspond to the speed and pitch values proposed by other authors and the 
historical record on pitch. 


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Buenos Aires 



Figure 14a 



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Camden 



Figure 14d 


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New York 


Mexico City 




Camden Buenos Aires 



The Victor data were also analyzed by recording location. 

The arrows in Figure 14e highlight where the charts appear to indicate some 
dominance. 

Here again we find the data peaks do not correspond to any anticipated pitch or 
speed values, with the exception of one peak in the Mexico City (Figure 14b) data for 
A=435, or 17 out of the 3,500 sample points. This is not statistically significant. 


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Varispeed by Year 

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Figure 15 


This scatter plot (Figure 15) distributes the data by catalog number. It clearly 
demonstrates a very wide dispersion in each of the subsets of the catalog periods 
represented in the data. 

The data does show a general slowing of the record speed over approximately 20 
years, in that the amount of speed correction necessary to bring the discs to A=440 
increases. Slowing the discs allows longer works to be recorded. 

An alternative explanation for this trend is that the reference pitch falls over this 
period. Since the historical record on pitch is an upward trend, this alternative 
explanation seems unlikely. 

Edison Diamond Discs 

The Library of Congress contract that specified the Victors be pitched to A=440Hz 
also specified the Edison Diamond Discs be speed adjusted to 80rpm. This speed 
selection is based on strong documentary evidence found in their corporate 
archives. 

This work on pitch discovery was performed only near the end of the job with the 
specific goal of gathering data for this study, rather than as required by the contract. 
There are only 


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218 data points. An additional 2,200 sides will be digitized, and the data will be 
gathered and analyzed in the same manner 24 . 


Edison Speed Offset (from 78) 

87 I 

7.0 

5.3 

3.6 

1.9 

0.2 

- 1.5 

- 3.2 

- 4.9 

- 6.6 

- 8.3 

- 10.0 

0 10 20 30 40 50 60 70 80 

Figure 1 6 

These early data show some interesting peaks that correspond to anecdotal 
information from other engineers that they often find Diamond Discs to fall not at 
80 rpm, but at 78.26 or 79.04rpm. 

This data is highly inconclusive. 


OKeh Records 

Speed variation (Figure 16) in the OKeh discs is also a random distribution. 


24 The work on additional Edison Diamond Discs will take place after the publishing 
deadline. 


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8.8 

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;h Discs 

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0 5 

0 1 ( 

)0 11 

50 2 ( 

)0 21 


Figure 1 7 


Mick Moloney Collection of Irish-American Music and Popular Culture, New 
York University 



The data drawn from the random labels in the NYU/Moloney Collection spans a 
larger time period than the other data sets, extending well into the electrical era. 

Might these data indicate a convergence toward 78.26 as the actual target speed of 
discs? Afterall, many of the challenges faced in the acoustic era working with purely 
mechanical systems, were either solved or improved over time with the regular use 
of reliable and accurate electric motors and standard line frequencies of 50Hz and 
60Hz. 


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Additional Information on Speed Determination 

We embrace that 78.26rpm may not equal A=440Hz, but we want it to equal 
something. However, might we be imposing our early 21 st century expectations on a 
late 19 th century culture? Consider the following three anecdotes. 

First: Attendees of the 2011 IASA Conference in Frankfurt were treated to a 
performance by the Sixtonics. The concert included a live recording demonstration 
using restored early electrical recording equipment. When the resulting lacquer disc 
was played back, one of the musicians asked why it played at a pitch higher than 
they had just performed? The drag of the cutting stylus had slowed down the lathe 
during recording. When the disc was played back there was less resistance and the 
turntable played up to speed. 

What is the proper way to play back this disc? At the originally performed 
pitch, or the pitch that would have been experienced in the home? 

Do we assume it took 100 years for someone to notice this phenomenon? Or 
is it merely the case that 100 years ago pitch varied so widely it was taken for 
granted? 

Might the 79.04 speed observed in the small Edison sample correspond to 
this demonstration? 

Second: In 2011 your author recorded all 14 Bach keyboard concerti on a collection 
of restored antique harpsichords. The instruments were built between 1627 and 
1707. When the instruments were built, pitch was trending from A=392 to 415. 
During restoration each instrument was pitched differently according to the 
tradition of when and where it was originally made. To avoid strain on the 
instruments, and many broken strings during the recording, all the instruments 
were retuned to a compromise pitch of A=400, a pitch with no historical foundation 
whatsoever. Other recordings have been made with these instruments in solo or 
continuo roles. In those recordings, made in the span of a few years, the instruments 
were tuned to their native pitches: 392, 405, 407, 410 and 415. If these had been 
among the Victor, OKeh and Moloney discs in this study pitched to A=440, every one 
would be mis-represented, and each in a different way. 

To anyone who presumes to know exactly the correct pitch to play any given 
acoustic era disc, we offer the following YouTube video. 

• https://www.youtube.com/watch?v=UnhlOUBsd6g 


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Summary Conclusions on Speed Determination 

• Analysis of 4 data sets totaling 9,000 sides, of pristine discs, worn discs and a 
random selection of labels, demonstrates no clear pattern to definitively determine 
the speed or pitch of acoustic era 78rpm recordings. 

These findings inform the process of preservation. It is necessary to use the proper 
stylus because it is not possible for the listener to alter that choice. Speed, on the 
other hand, can be changed when playing a digital file. In practice it may make sense 
to choose a fixed reference (speed or pitch) for playback and leave it to the user to 
decide; and to provide multiple playbacks with different styli, and again leave it to 
users to chose which they prefer. 


Acknowledgements: 

John Bolig, Victor discographer extraordinaire 
Sam Brylawski, University of California Santa Barbara 
Mari Carpenter, Travis Kirspel and Keith Minsinger 

Eldridge Johnson Museum, Delaware State Division of Historical and Cultural 

Affairs 

Brian Destremps, Senior Audio Engineer, George Blood, LP 
Caitlin Hunter, Patrick Smetanick, Gene DeAnna, Library of Congress 
Morgan Oscar Morel, IT Systems Admin, George Blood, LP 
Kimberly Peach, Lead Archivist, The Winthrop Group 
Kimberly Tarr, Head, Media Preservation Unit, New York University 


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